In that case: Master1<- Master
Master1$zGPA<-sapply(seq_len(nrow(Master1[,-1])),function(i) weighted.mean(Master1[i,-1],Units)) Master1$zGPA #[1] 0.035121951 -0.003902439 0.097804878 all.equal(Master,Master1) #[1] TRUE A.K. ________________________________ From: Robert Lynch <robert.b.ly...@gmail.com> To: arun <smartpink...@yahoo.com> Sent: Monday, July 22, 2013 6:35 PM Subject: Re: [R] weighted average weighted.mean is the function. My apologies for appending an s On Mon, Jul 22, 2013 at 3:31 PM, arun <smartpink...@yahoo.com> wrote: Hi, > >I couldn't find the function `weighted.means` using ?weighted.means or >??weighted.means. It would be useful to provide the library information. > > > > >----- Original Message ----- >From: arun <smartpink...@yahoo.com> >To: Robert Lynch <robert.b.ly...@gmail.com> >Cc: R help <r-help@r-project.org> >Sent: Monday, July 22, 2013 6:26 PM >Subject: Re: [R] weighted average > >Hi, >May be this helps: >Master<-read.table(text=" >SID B2A B2B B2C C2A C2B C2C C118A C118B C118C >001 0.01 0.5 -0.4 1.2 -1.8 0.3 -0.3 0.4 0.5 >002 0.01 0.5 -0.4 0.5 -0.4 1.2 -1.8 0.3 -0.3 >003 0.04 0.05 0.5 -0.4 -0.5 0.4 -1.2 1.8 0.3 >",sep="",header=TRUE) > library(matrixStats) > > > Master$zGPA<-rowWeightedMeans(as.matrix(Master[,-1]),Units) > Master ># SID B2A B2B B2C C2A C2B C2C C118A C118B C118C zGPA >#1 1 0.01 0.50 -0.4 1.2 -1.8 0.3 -0.3 0.4 0.5 0.035121951 >#2 2 0.01 0.50 -0.4 0.5 -0.4 1.2 -1.8 0.3 -0.3 -0.003902439 >#3 3 0.04 0.05 0.5 -0.4 -0.5 0.4 -1.2 1.8 0.3 0.097804878 >A.K. > >----- Original Message ----- >From: Robert Lynch <robert.b.ly...@gmail.com> >To: r-help@r-project.org >Cc: >Sent: Monday, July 22, 2013 6:12 PM >Subject: [R] weighted average > >I am trying to compute GPA from class grades(which have been normallized) >I have for example the following matrix > >Master = >SID B2A B2B B2C C2A C2B C2C C118A C118B C118C >001 0.01 0.5 -0.4 1.2 -1.8 0.3 -0.3 0.4 > 0.5 >002 0.01 0.5 -0.4 0.5 -0.4 1.2 -1.8 0.3 > -0.3 >003 0.04 0.05 0.5 -0.4 - 0.5 0.4 -1.2 1.8 > 0.3 >etc > >Where each column has a zero mean and a standard deviation of 1. I want to >calculate a weighted average for each row(student ID) that takes into >account that >B2A, C118A, C118B, and C118C are all 4 unit classes, and the rest, B2B, >B2C, C2A,C2B,C2C are 5 unit classes > >I have tried >Units<-c(4,5,5,5,5,5,4,4,4) >Master$zGPA <-weighted.means(Master[,2:10],Units) > >But that gets me one number and not a vector. > > [[alternative HTML version deleted]] > >______________________________________________ >R-help@r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
